I worked out this formula B=Bg/4π√(εG)
Where B is the magnetic flux density at the surface of the Earth or a body, Bg is the gravitomagnetic field of the Earth or a body, ε is the permittvity of free space and G is the gravitatonal constant.
I realised that when I substitute the Bg of the Earth, B concided with the experimentally measured magnetic flux density of the Earth's surface.
Could this be the relation ?